1. Field of Invention
The field of this invention relates to an Edible Pet Chew and a method for making the edible pet chew.
2. Description of Related Arts
Domestic pets, primarily dogs, have an instinct to chew which keeps their teeth healthy, exercises their jaws and teeth and keeps teeth clean. “Pet Chew” products have been introduced to the market for many years to accommodate that instinctive urge to chew in a healthy direction.
“Pet Chews” are intended to be chewed by a pet/dog for an extended period of time, being distinguished from “pet treats”. “Pet treats” are intended to be chewed by a pet/dog for a relatively short period of time and digested.
One existing important category of a typical Edible “Pet Chew” is the ones that are made of animal skin, for example Rawhide/Porkhide sheet. Of these types of pet chew, “rawhide sheet” is a commonly used material which is thin, chewy, malleable and long-lasting for chewing. With these excellent properties/characteristics, “rawhide sheet” is extremely extensively used to produce dog chews in existing market creating thousands of “rawhide” dog chew products. One specific such pet chew is disclosed in U.S. Pat. No. 2,988,045 to Fisher. This pet chew includes a rolled and knotted sheet of rawhide resembling a bone shape. To make the bone shape, a sheet of wet rawhide is rolled into a cylindrical form, and while the rawhide is still wet, two the ends are knotted to simulate an animal joint. Then the rolled and knotted rawhide is dried and hardened.
Pet Chew consisting solely of rawhide/porkhide sheets may be chewed for sufficient long time and can be digested. However, many dogs find these pet chews lack of substantial flavor and scent. Accordingly, many dogs lose interest with these rawhide pet chews after a while and will at most only chew on them for short periods of time. Some existing products consisting solely of rawhide/porkhide are improved by adding additional flavorings, for example artificial peanut flavor, into the rawhide after it is hardened, but it cannot improve the palatability of rawhide significantly.
U.S. Pat. No. 5,673,653 discloses an edible pet chew wrapping jerky with rawhide, so as to attract pets to chew. It finds a good way to make the pet chews made of rawhide/porkhide sheet quite attractive to pets/dogs, improving its palatability to pets. But since it still has a big member of rawhide/porkhide in the finished products as outer layer, it unfortunately is not thought to overcome the other two disadvantages that rawhide/porkhide have as described below.
The other two disadvantages of Pet Chew formed from solely or substantially rawhide/porkhide are as follows. Firstly, environmental pollution. It is concerned by many people that manufacture of rawhide is relatively unregulated industry. Producing the raw material of rawhide is known to use a bunch of chemicals and therefore generate evident pollution during its splitting, cleaning, washing and bleaching processes. The water system may also be harmed and polluted accordingly. Secondly, detrimental residues in rawhide from primary processing. When primarily processing rawhide, lime solution, NH4CL, H2O2, and NaOH may be used during its splitting, cleaning, washing and bleaching processes and may remain in some finished products more or less. These chemicals are not good for pets' health. For example, excessive H2O2 will cause pets vomit or even worse symptom. What's more, heavy metals, for example lead may also remain in the rawhide and accumulate in the body, which cause serious damage to the pets' health. These concerns encourage a perception for pets/dogs owners to look for alternative ways to provide a “pet chew” for a pet without the use of rawhide/porkhide.
The U.S. Pat. No. 5,673,653 has another disadvantage regarding the member of “traditional jerky” or “kippered jerky” wrapped inside the rawhide sheet. The disadvantage is, U.S. Pat. No. 5,673,653 fails to teach the “traditional jerky” or “kippered jerky” is a meat based sheet member processed with an improved formula and/or by a specific process, wherein the formula and process are intended to achieve good malleability, rigidity, strength and durability of the meat based sheet to simulate the malleability, rigidity, strength and durability of the property/characteristics/chewing functions of traditional rawhide/porkhide sheets (the rawhide/porkhide sheets is for making dog chew products). The “traditional jerky” or “kippered jerky” prepared by the patent isn't chewy at all and is found to be brittle creating a lot of fragment of jerky inside sales package which isn't valuable for consumers. Due to this disadvantage, the dog chew products disclosed by U.S. Pat. No. 5,673,653 only has the outer layer rawhide member chewy. The “traditional jerky” or “kippered jerky” wrapped inside isn't intended to serve as a chewy member for dogs to chew on for an extended time as rawhide sheet member does. It only serves as an attractant rather than an additional chewy member.
In another category of “pet treat”, there are animal meat product lines, typically, chicken jerky, pork jerky and beef jerky, which are substantially made of meat ingredients. It is known to all that pets, primarily dogs welcome meat jerky very much. The range may cover dried products, including animal meat, such as chicken, pork, beef, duck meat, goose, turkey meat, poultry meat, fish and animal pizzle, animal viscera, such as liver, lung, and heart, etc. Typical processing of meat jerky is, simply obtain meat from slaughtered animals, add additives (for example salt, sugar, plant protein and preservatives), then dry it. However, one disadvantage of these jerky products is, after meat being obtained from animals, the meat is not formulated properly and/or is not processed properly before making the finished meat products, and therefore the materials don not present good rigidity, durability and strength for dogs' long time chewing. Either the materials do not present good malleability to form a pet chew product. As a result, the finished products have limited shapes/forms/structure and can not be formed into various shapes (for example shape of sheet like a rawhide sheet) welcome by the pets or the pet owners. Some of these jerky products are made of ground meat added with simple additives (for example salt, sugar), being shaped with a mold thin enough looking like a “sheet”. But the manufacturers fail to learn to follow a proper formula and/or process to form the “sheet”. As a consequence, these “sheets” do not have the essential properties/characteristics that “rawhide” has. These jerky sheets are fragile, crisp, and not chewy, unlike rawhide. Therefore manufacturers do not use them to form the finished products that “rawhide sheet” is always formed to. Another disadvantage is, these meat lines are always classified as “pet treat”, which means they are intended to be chewed by a pet/dog for a relatively short period of time before being fully digested, unlike “pet chews”.
U.S. Pat. No. 7,677,203 discloses an edible pet chew against U.S. Pat. No. 5,673,653, replacing the rawhide with a “plant based” material sheet with over 50% plant material, so as to avoid pollution and health damage. However, since dogs are carnivorous, the plant based material does not attract pets very much. Although flavoring can be added into the material, the plant based sheet member of the edible pet chew is still less attractive to dogs due to too high plant percentage (over 50%) existing in the formula, since dogs do not prefer vegetal material. It results the plant based sheet member of the edible pet chew products lack of inherent attraction to dogs. Furthermore, compared to plant based food, bodies of pets, especially dogs, more fit nutrition provided by animal based food, and their digestive system more fits animal based food, such as meat. Therefore, the “plant based” edible pet chew with over 50% plant ingredients is not considered to be so sufficient to pets' health. Another disadvantage is, the U.S. Pat. No. 7,677,203 fails to teach the “plant based sheet” is the one processed by a specific process, wherein the process is intended to achieve good malleability, rigidity, strength and durability of the plant based sheet to simulate the malleability, rigidity, strength and durability of the property/characteristics/chewing functions of traditional rawhide/porkhide sheets (the rawhide/porkhide sheets is for making dog chew products).
Another existing pet chew made from plant material is the one made from a molded wheat based material with glycerin, gelatin, monoglycerides of edible fatty acid and natural flavor with three-dimensional-shape. It also contains chlorophyll intending to improve dogs' breath. This molded plant material composition is molded into an elongated shape with one end shaped like a toothbrush head and an opposite end shaped like an epiphysis i.e. end of a long bone. However, this pet chew formed from main ingredients of plant also has the same disadvantages as U.S. Pat. No. 7,677,203 does.
U.S. application Ser. No. 12/925,509, filed Oct. 22, 2010, disclosed an edible pet chew comprising an outer layer and an inner layer. The outer layer comprises 28-49% plant based material, at least 30% meat based material and at least 20% animal hide based material. The first disadvantage of the application Ser. No. 12/925,509 is that, the application fails to teach how much meat and plant ingredient exactly existing in the outer layer member since verbiages of “plant based material” and “meat based material” are vague ones to describe an ingredient. The second disadvantage of the application is that, the outer layer contains too high percentage animal hide based material, as much as at least 20%. The too high percentage animal hide based material brings significant disadvantage concerns of rawhide material as described at above Paragraphs. To put it simply, environmental harm when processing rawhide, detrimental residues in finished products. The too high percentage animal hide based material will result in the outer layer having a surface with roughness or bumps or ridges or irregularities, which isn't visually attractive for dog chew consumers. The third disadvantage of the application is that, it introduced a member of outer layer only rather than a “sheet” member, which makes it fail to simulate the sheet shape of traditional popular rawhide/porkhide sheet dog chew and thus not visually attractive as rawhide/porkhide sheet is. The fourth disadvantage of the application is, the application Ser. No. 12/925,509 fails to teach the “outer layer” is the one processed by a specific heating process before its being extruded at the extruder die, wherein the process is intended to achieve good malleability, rigidity, strength and durability of the outer layer to simulate the malleability, rigidity, strength and durability of the property/characteristics/chewing functions of traditional rawhide/porkhide sheets (the rawhide/porkhide sheets is for making dog chew products). The fifth disadvantage of the application is that, the application Ser. No. 12/925,509 merely teaches the pet chew must be in two layer structure. It fails to teach a pet chew with merely a single sheet. Compared to the single sheet constitution, disadvantages of two sheet or two layer constitution are, it requires more labor to have the second sheet wrapped in the product and requires additional materials to make the second sheet, which isn't cost economical.
Accordingly, what is needed is an edible pet chew to overcome the problems and disadvantages of the prior arts.